1. Field of the Invention
This invention relates to absorption heat transfer systems using multiple sources of heat input for generator heating and more particularly the control systems for monitoring and optimizing the use of each of the multiple sources of heat input.
2. Background
Absorption heat-transfer machines comprise a family of heat energy driven machines that can provide heating, cooling or both heating and cooling. Hundreds of thermodynamic cycles and working fluids are utilized and/or described in the literature. The fluid used in the operation of these systems is typically called a solution pair or strong solution and includes ammonia-water and lithium bromide-water pairs. Energy sources include, but are not limited to, combustion of fossil fuels (e.g., natural gas, propane, liquified natural gas (LNG), oil, methane, butane, waste oil, wood, and other biomass), solar heating, and unused and waste energy streams. Waste energy streams include, but are not limited to, flue (exhaust) gas from combustion engines, turbines, industrial and commercial processes, fuel cells, cooling loops for combustion engines, turbines, fuel cells, and industrial and commercial processes. These heat sources are available in gas or liquid forms. Absorption heat-transfer machines can be fired by single heat sources or multiple heat sources as set forth in U.S. Pat. No. 6,250,100 and U.S. Pat. Appln. Pub. No. 2003/0000213 A1. When multiple heat sources are used, one or more of the heat sources can be available only part of the time, or in partial quantity, at any given time when operation of the heat pump is desired. However, currently there are no reliable methods of controlling which of the various heat sources are used or the quantity of heat to be provided by each source.
As such, it is an object of the present invention to provide a control method for selecting a particular heat source from two or more heat sources to be used at a given time for heating an absorption heat-transfer device.
It is another object of the present invention to provide a control method for determining the amount of heat to be provided by each heat source when two or more heat sources are available.
It is another object of the present invention to determine available heat sources when two or more heat sources are used.
It is another object of the present invention to use the energy available from two or more heat sources in a cost efficient manner.